A spot light is designed to direct a concentrated beam of light over a designated area at a distance. At present, there is no LED light which can be used to illuminate intensively and effectively for both far and near distance with the same apparatus and consume low power. If a LED light needs to provide a high intensity beam over a long distance, it commonly combines an array of high power LED chips on a planer circuit board and a parabolic concave reflective mirror or a large lens as illustrated schematically in FIGS. 1 and 2. These current approaches have drawbacks such as: (1) Optical principle for diverging or converging light beams only applies to a single point light source. The size of the LED chip array mandates that the light source cannot be a single point. Light beam divergence or convergence cannot be controlled (see FIGS. 1 and 2). This characteristic limits the effective illumination at a distance. Multiple rings of uneven brightness will be observed at a distance. (FIG. 3); (2) Aberration and distortion are significant. It is very difficult to evenly illuminate an area far away; (3) Illuminating power is fairly weak over a distance because most of the light beams are diverged away from the intended target spot. In order to get greater illumination, the LED chips are fed with higher power. Consequently, the light will waste much power, generate a lot of heat and shorten the life of the LED chips; (4) Lenses are usually not designed specifically to suit the optical characteristic of LED chips; (5) Focus adjustable light usually has a mechanism to adjust the position of light source relatively to the lenses or the reflective mirror. Common focus adjustment mechanism is vulnerable to recoil, shock, vibration, lateral force impact and potential water or air leakage.
Hence there is a need for versatile LED lights with low power consumption that can deliver high intensity light beams over a long distance with adjustable focus and direction. In some situations, it would be best that these lights are waterproof and shock proof as well.